Hydrogen which is one of the energy storage media has a high possibility of energy career. We have proposed the Totalized Hydrogen Energy Utilization System (THEUS) for applying to commercial buildings. THEUS is composed of fuel cells, water electrolyzers, hydrogen storage tank and their auxiliaries. THEUS contributes to electric power load leveling, providing a stable supply of power for emergencies, and energy-saving for building energy consumption. We have developed the hydrogen storage tank using metal hydride alloy. This paper presents operation control methods to use hydrogen reaction heat efficiently in actual operation. The mathematical model of the multiple metal hydride tanks has been developed by which it is possible to reproduce driving. Several methods for controlling the operation of multiple metal hydride tanks, which would likely be used in actual operation, is proposed. Effects of actual load patterns and proposed methods were investigated experimentally and numerically on multiple metal hydride tanks operation. From the comparison between calculated results and experimental results, it is confirmed that the mathematical model calculation can estimate the driving behavior of the multiple metal hydride tanks. Then, multiple tanks control pressure values of each actual load pattern were determined for the operation efficiency optimization by the mathematical model. Method B2, with the water circulation pipes connected in series and the multiple metal hydride tanks control, could obtain cold source with high efficiency.

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